1. Technical Field
Various embodiments of the present invention relate to patient wound care, and more specifically, to systems and methods of wound coverings and dressings.
2. Description of Related Art
Since the mid-20th century various types of rudimentary vacuum-assisted devices have been used to facilitate coverage and closure of open wounds. Conventional vacuum-assisted wound care devices use a non-unified, piecemeal wound filling material sealed with an adhesive film, and a vacuum pump that maintains negative pressure on the wound while draining the effluent from the wound into a fluid collection canister.
There is sometimes a need to modify the wound dressing to provide a shape conforming to the wound. In a common conventional system this is done with wound filler material, often made of an open-cell reticulated polyurethane sponge material or cotton gauze. The sponge wound filler material—often black in color, or otherwise opaque—must be cut to the shape and contour of the wound. This material is not particularly easy to cut to shape, generally resulting in multiple odd shaped pieces of sponge that need to be held in a piecemeal fashion within the wound until an adhesive film can be placed to seal the dressing. The present inventors recognized drawbacks in using this piecemeal approach. These drawbacks exist for the known conventional wound fillers used in negative pressure wound therapy devices.
Different ways of filling the wound cavity have been attempted for the application of negative pressure wound therapy. U.S. Pat. No. 6,752,794 to Lockwood (Lockwood '794) describes irrigation and vacuum passageways created as channels in a solid noncompressible non-porous member. (See Lockwood '794, FIGS. 12 and 35). Lockwood '794 uses separate ports for vacuum and irrigation. However, one of the several limitations of this design is that the vacuum passageway between the wound bed and the dorsally located vacuum port can only occur through the limited number of perforations placed within the solid noncompressible member and that which traverses around the periphery of the member. Additionally, the communication between irrigation source tubing and the dressing member is explicitly demonstrated with a peripheral/horizontal plane attachment site, which is believed to be inherent to the design described in the Lockwood '794 patent. This limits the ability to custom cut any portion of the periphery of the member to the dimensions of each wound. Likewise, the irrigation passageways specifically stop short of the peripheral extent of the irrigation member.
There are also drawbacks relating to the vacuum regulation system of conventional devices. Conventional negative pressure wound treatment (NPWT) devices often make broad reference to not placing the dressing in proximity to vascular structures. However, the conventional systems do not specify what would be a safe distance from these structures. Since all portions of the body are “in proximity” to vessels, these conventional systems provide no means for mitigating the risk of exsanguination. There have been catastrophic complications, even leading to patient deaths, related to exsanguination events reported to the Federal Drug Administration (FDA) and Centers for Medicare and Medicaid Services (CMS) for certain conventional NPWT systems.
While use of NPWT has become increasingly widespread in the last two decades, the technologies available in this field remain narrowly focused, and are subject to the aforementioned drawbacks and a number of other shortcomings. Moreover, the present inventors feel NPWT is not a stand-alone concept, but that it is a piece in the overall wound care process. The management of open wounds from trauma or disease, with the assistance of NPWT, could benefit from the application of multiple other features which are not provided by any conventional NPWT system. One significant limitation of current art is the lack of a method for integrating most or all of the commonly used methods of wound care into a single mechanical system.